Transmitter



March 11, 1941. c POTTER r L 2,234,318

TRANSMITTER Filed July 1, l9 40 lllll llll Illlllllll Patented Mar. 11, 1941 PATENT OFFICE TRANSMITTER Charles E. Potter, Richmond Heights, and James W. Kendall, St. Louis, Mo.; said Kendall assignor to said Potter Application July 1, 1940, Serial No. 343,424

7 Claims.

This invention relates to transmitters for transmitting electric signals, of a character which areused for transmitting signals automatically in response to conditions which are to be supervised.

' The-transmitters are of a type which have been employed, for instance, in supervising sprinkler systems, although they may be employed in other environments. When used in sprinkler systems they are made responsive to a number of different conditions. They have been made responsive to'water levels in a gravity tank, to pressure in a. pressure tank, to flow through a conduit, and too. valve setting; That is to say, they will be installed in 'a system in sucha manner as to remain quiescent during normal conditions, but whenthese conditions change proper mechanism willitrip the-transmitter giving a code signal at a central station, or at a point remote from the installation of the transmitter; They are connected at times directly with mechanical means which are influenced by the conditions to be supervised. Other times the transmitters of this type are controlled by an electric relay influenced by an electric circuit which is opened or closed automatically by mechanism under the influence of'those conditions. In the latter case the transmitter itself may be somewhat remote from the location ofv the conditions to be supervised. The 30. specific use or application of the transmitter is no part of the invention. The art will understandhow the. transmitter may be applied 'to useful purposes.

The improvements here involved relate more particularly to means for controlling the transmitter. A transmitter of this type includes a spring motor and a' code wheel rotated by the motor. and interrupting a finger pile-up switch, and. the improvement here relates to the motor 40" blocking: and releasing mechanism in a transmitter.

Anobject oi, the invention is to provide means which are simple in construction and positive-in operation for controlling such a transmitter. A

45". iurther object to. providecontrolling means which will permit. the transmitter to operate to give a predetermined signal after it has been tripped (for instance, in response to an abnormal condition), then. to stop the transmitter, and

50; then=to-givea predetermined restore. signal, .afterconditions which caused the. instrument to be tripped-have been restored to normal. Other and specific .objects will be apparent fromthefollowing detail description, taken in 55. connection with: the" accompanying drawing.

Fig. 1 is a front elevation of a transmitter embodying the present invention;

Fig. 2 is aside elevation;

Fi 3 is an elevation of the control mechanism in one extreme position;

Fig. 4 is a View similar to Fig. 3, with the control mechanism in an intermediate position; and

Fig. 5 isa view similar to Fig. 3, with the mechanism in the opposite extreme position.

'I'he'transmitter'mechanism consists of a spring 10 motor having an escapement by which the motor can be blocked or released, a code sending wheel driven by the motor and interrupting a finger pile-up switch, and control mechanism for the motorinwhich, or in combination with which, 15 the present improvements and invention reside. The construction and arrangement is such that upon release the motor will drive the code wheel to interrupt the pile-up switch and thereby give a code signal which may be read at a remote 20 point or at a central station.

The spring motor, code wheel, and pile-up switch, aside from the control mechanism specifically illustrated in Figs. 3, 4 and 5 and except the combination therewith, are conventional, are 25 commereial'structures and are well known in the art. It will'be understood further that while one such particular structure has been illustrated other and similar devices may be used or controlled by the present improvements.

As specifically illustrated, a non-metallic code wheel I is positioned to operate a finger pile-up switch 2 which interrupts a circuit connected with a central station to give a code signal corresponding to the number and arrangement of teeth in the, code wheel I.

In the spring motor a main spring 3 has one end connected to a fixed post 4 in a frame memher, 5 and has its other end connected to a shaft 6, by whichthe spring may be wound and by which the motor is operated. This operation is caused through a train of gearing which includes a gear 1 attached to the shaft 6 by a pawl and ratchet connection, including a ratchet wheel 8 and a pawl 9, best shown in Fig. 1. The gear 1 drives a pinion I0, secured to a shaft I I, to which is secured the code wheel I. An escapement wheel I2 is driven by a, chain of gearing which includes a pinion I3 on'its shaft I I, which pinion is in mesh with a gear I5 secured to the shaft II. The escapement includes a pivoted balance I6 which carries an anchor I! to engage in the teeth of the escapement wheel I2, as best shown in Figs. 3, 4 and 5.

The arrangement is such that when the escape- 5 ment is not blocked and the spring 3 is wound the motor will turn the code wheel I continuously until the spring is unwound, or until the escapement is blocked; and during that operation the balance I6 will oscillate. Conventional means for blocking the escapement, and thereby stopping the motor, includes the abutment pin I8 secured to the balance I6.

The novel mechanism for controlling the operation of the spring motor includes a detent IQ for engaging the end of the abutment pin I8, as shown in Figs. 3 and 4, and thereby hold the pivoted balance in such a position that .a pallet on the anchor I-1 engages a tooth of the escapement wheel I2 and thereby blocks the motor.

The detent I3 is mounted to rock or oscillate and is so shaped that it will engage the abutment pin IE! to stop and hold the motor when the detent is in either of two extreme positions, as shown in Figs. 3 and 5, and will release the pin I9 when at an intermediate position, as shown in Fig. 4. To accomplish this, the end of the detent I9 is bifurcated, having two extended forks either of which will engage the end of the pin I8, While releasing the pin when the detent is moved to an intermediate position by permitting the pin I8 to oscillate between the forks, as'shown in Fi 4.

The detent I9 is a part of a unitary member which includes a boss 20 pivotally mounted on a pin 2I and extends as a radial arm therefrom. The member which includes the boss 20 and the detent I9 also has radial extending arms 22, 23 and 24. The arm 22 is a cam follower; the arm 23 is the means by which external force is applied to operate the device; and the arm 24 is a radial pin for engagement with a governing pawl 25.

For operating the control mechanism or the detent, external force may be applied to the end of the lever 23 by any suitable mechanism. One such mechanism is a relay or the armature of a relay; another is linkage connected or moved by mechanism responsive to certain conditions to be supervised. The connection between the operating devices and th lever 23 may be a yoke with a lost motion but which is suitable for pressing the lever in either of two directions, as indicated by the arrows in Figs. 1, 3 and 5. The arrows in the figures indicate the direction that the force must be applied to move the mechanism from the position or condition shown in the respective figures. Since means for applying force to move the lever 23 forms no part of this invention are well understood in the art, and can be devised without invention, no specific structure is shown in the drawing.

The lever 22 is a follower which cooperates with a cam 26 to control the transmitter in such a manner that when force is applied to the lever 23, responsive for instances to abnormal conditions, the spring motor will cause the code wheel I to be revolved a certain number of revolutions, three as specifically shown in the drawing, and then the motor will be stopped. This operation will start from the position shown in Fig. 3, the external force being applied to the lever 23 in the direction shown by the arrow in that figure. After this signal has been given the mechanism will come to rest in the position shown in Fig. 5. Then subsequently, for instance when normal conditions have caused force to be applied to the lever 23 in the direction as shown in Fig. 5, a restore signal will be given which, in the embodiment specifically illustrated in the drawin will be by two rotations of the code wheel I.

The follower 22 cooperates with the cam 26 by means of an inwardly extending portion on the outer end of the lever or follower 22 which rides in a track or groove on the face of the cam 26. This groove has generally a circular contour, but more specifically has a notch 21 on the outer periphery of the groove, a circular portion 28 counterclockwise from the notch 21, 216 as specifically shown in the drawing, to an inner notch 29, and then a circular portion 30, 144 to the notch 21. The cam 26 has gear teeth on the periphery and meshes with the gear 1, and as specifically shown the teeth on the cam 26 and the gear 1 are equal in number. While the gear ratio between the gear 1 and the cam 26 is even, the ratio between the gear 1 and the pinion H), which drives the code wheel I, is five to one. Therefore, the code wheel I, as specifically shown, is rotated five times for each revolution of the cam; or the code wheel rotates three times while the follower traverses the portion 28 of the groove and two times while the follower traverses the portion 30 of the groove.

With the foregoing description of the cam the operation of the device may now be more fully explained.

The arrangement shown in Fig. 1 and Fig. 3 is the normal condition of the apparatus, ready to respond to applied force caused, as it may be said, by abnormal conditions. In this condition it will be observed that the spring motor is blocked by the engagement between the pin I8 and the lower fork of the detent I9. When force is applied to the lever 23 in the direction of the arrow,

as shown in that figure, the follower 22 will be moved out of the notch 21 toward the center of the cam, and the detent will be lowered to the position shown in Fig. 4, in which the pin I B may reciprocate between the prongs of the de tent I9. The spring of the motor being wound and the motor being free to operate, it will commence to turn the code wheel I to give a signal and the operation will continue, as shown in Fig. 4, until the notch 2-9 reaches the follower, at which time the follower will tall into the notch 29 and the motor will be stopped by contact between the upper prong of the detent I9 and the pin I8, or after the code wheel has been turned a total of three revolutions. The machine will then be in the position shown in Fig. 5.

Then when the conditions which are supervised have been returned to normal, causing force to be applied to the lever 23 in the direction shown by the arrow in Fig. 5, the follower 22 will be moved out of the notch 29 and will ride the outer periphery of the groove in the portion 30 thereof until the follower is reached by the notch 21, when the follower will fall into.

that notch and the mechanism will again assume the position shown in Fig. 3. By the last operation the code wheel will have been caused to turn two revolutions,.giving what may be described as a restore signal, and indicating that conditions are again normal. The apparatus will then be in condition to respond to give another signal or another cycle of signals.

The operation of the device has been specifically described as it would operate in a particular application, where it is intended to give a signal when tripped by mechanism which is responsive to abnormal and normal conditions. This explanation is given to more perfectly ex plain the operation, use and utility of the de-' vice, butv itis to. be; understood that this explanation and. descriptionis: given. 3/ way of; illustration and not by way-of limitation,

The mechanism, includes; an armor pin: 24 I! which cooperates with a governing or directional faces 33, and 34. The purpose of the pin 24 and.

pawl is to give the: follower 22. a directional urge. Thus, after-force has been applied in the direction asshown by the arrow in. Fig.3, to move the follower out of the notch- 27, the boss 20 will be rotated so that the point. of the pin 24 engages on the inclined surface 34 (see Fig. 4), thus urging the followerv toward the inner periphery of the. groove. But when force is applied in the direction of the arrow, as shown in Fig. 5, to move the follower 22 out of the notch 29, the pin-Will engage the surface 33 to urge the follower along the outer periphery of the portion and into the notch 21 when that notch reaches the follower.

In some installations the pin 24 and pawl 25 are unnecessary, that is when the installation is made in such an environment that force will be applied constantly on the lever 23 for a substantial period of time. For instance, if force is applied in the direction of the arrow as shown in Fig. 3, to move the follower out of the notch 21 and that force is continued until the notch 29 reaches the follower, then of course the pin 24 and the lever 25 are unnecessary, because the force itself will tend to urge the follower into the notch 29. Where, however, the transmitter is expected to respond to a momentary urge then the pin 24 and pawl 25 will insure its correct operation.

The particular contour of the track cooperates with the directional pawl 25 to assist it in accomplishing its functions. The arrangement is such that the follower is caused to travel along the inner periphery of the track portion 28, and along the outer periphery of the track portion 30 so as to insure the action of the directional pawl 25. This contour arrangement of the cam track comprises a straight portion adjacent the notch 21 and an extended portion 36 adjacent the notch 29. A weak or fluttering pressure against the lever 23 may be sufiicient to trip the motor but insufiicient to throw the pin 24 off center with respect to the pawl surfaces 33 and 34. However, the straight portion 35 guides the follower toward the inner periphery of the track so that the pin 24 is thrown off center allowing the pawl 25 to function. It is usually unnecessary as in the particular embodiment, to make the portion 35 straight since it is intended that the follower be moved out of the notch 29 (Fig. 5) by a restore operation, which will give a strong positive sufficient to clear the projection 36.

In the accompanying drawing and in theforegoing description, a specific embodiment of the invention has been specifically illustrated and described. It will be apparent that various changes may be made in the details of construction, within the scope of the appended claims, various improvements may be made, and parts of the invention may be used without the whole. While certain definite uses have been suggested for the transmitters, those uses are suggested by way of description to aid in understanding the invention, but the utility of the transmitters is not limited by those uses.

We claim;

1.- In; a, transmitter having a. springmotor and.

a code wheel rotated by the motor, the improvement. comprising a rocking detent constructed:

and arranged. .to stop the motor when. moved to either of two extreme positions and to release the motor when in intermediate position, a tripping member connected with said detent and adapted to receive an external applied force by which the detent may be moved from extreme positions toward the intermediate position, a camv driven by the motor, a follower cooperating with. the camand connected with the detent, the cam having points in its contour allowing the follower to assume positions permitting the detent to move to said' extreme positions and having a contour intermediate said points to hold the detent by means of the follower in the intermediate position for a-predet'ermined amount of rotation of the code wheel after the detent has been moved to the intermediate position and released the motor, and a spring pressed governing pawl connected and arranged to urge the detent toward either of the said extreme positions after it has been moved to the opposite extreme or intermediate position.

2. In a transmitter having a spring motor, a

code wheel rotated by the motor, and a detent for blocking and releasing the motor, the improvement comprising a rotating cam having a continuous track with notches interposed at selected angular positions rotated by the motor and a cam follower connected with the detent, the cam track being arranged to hold the detent in releasing position for a predetermined amount of rotation of the code wheel after the detent is released by a force applied to it in one direction, and then to hold the detent in releasing po sition for a different predetermined amount of rotation of the code wheel after the detent is re leased by a force applied t the detent in the opposite direction.

3. In a transmitter having a spring motor, a code wheel rotated by the motor, and a detent for blocking and releasing the motor, the improvement comprising a cam geared to and rotated by the motor and a cam follower connected with the detent, the cam having a continuous track with notches interposed at selected angular positions including two separate sections, each arranged to guide the follower so as to hold the detent in releasing position, and oppositely positioned surfaces between said sections for guiding the follower to permit the detent to block the motor.

4. In a transmitter having a spring motor, a code wheel rotated by the motor, and a detent for blocking and releasing the motor, the im provement comprising a cam disk geared to and rotated by the motor and a cam follower connected with the detent, the disk having on its face a continuous groove with notches interposed at selected angular positions including two separate concentric sections arranged to hold the detent in releasing position, and oppositely positioned eccentric notches between said sections for guiding the follower to permit the detent to block the motor.

5. In a transmitter having a spring motor and a code wheel rotated by the motor, the improvement comprising motor blocking and releasing mechanism including a cam driven by the motor, a unitary pivoted member and a directional pawl having means for biasing the unitary pivoted member in opposite directions, the unitary memher having a boss, a radial arm extending from the boss carrying a detent to block and release the motor, a radial arm adapted to receive an external applied force to rock said member, a radial arm comprising a follower for the cam, and a radial pin so cooperating with the directional pawl that the follower is given a directional urge in opposite directions.

6. In a transmitter having a spring motor and a code wheel rotated by the motor, the improvement comprising motor blocking and releasing mechanism including a cam having a continuous track with notches interposed at selected angular positions driven by the motor, the cam track having a straight portion, a unitary pivoted member and a directional pawl having means for biasing the unitary pivoted member in opposite directions, the unitary member having a boss, a radial arm extending from the boss carrying a detent to block and release the motor, the

directional pawl so cooperating with the straight portion of the continuous cam track through the unitary member that the detent is given a direc tional urge in opposite directions.

7. In a transmitter having a spring motor, a code wheel rotated by the motor, and a detent for blocking and releasing the motor, the improvement comprising a cam having a continuous track with notches interposed at selected angular positions rotated by the motor and a cam follower connected with the detent, the cam track having a straight portion, a directional pawl, the directional pawl so cooperating with the straight portion of the continuous cam track through the cam follower that the detent is given a directional urge in opposite directions.

CHARLES E. POTTER.

JAMES W. KENDALL. 

